Distributional context reweights duration-related activity across timing-related regions

Abstract

Duration judgments are calibrated by the statistics of recent temporal experience, but how this contextual influence is expressed across human timing-related brain regions remains unclear. We used functional MRI while 24 participants performed a visual temporal bisection task under two distributional contexts: one biased toward longer durations and one biased toward shorter durations. Behaviorally, distributional context shifted subjective duration judgments without changing in temporal precision, consistent with a prior-related bias. Neurally, duration-related BOLD responses varied across a priori timing regions as a function of context. The clearest region-specific evidence was stronger left-insula duration modulation in the short-biased context. SMA/pre-SMA contributed to the broader timing-network pattern, and its context-specific asymmetry was sensitive to the alignment of the duration regressor. Exploratory SMA-seeded connectivity analyses provided converging evidence that context also modulated duration-related coupling with timing- and attention-related regions. Together, these findings indicate that distributional context impacts the relative weighting of established timing-related regions during duration judgments, rather than recruiting anatomically separate timing systems.